feat: 添加 :new 系统命令创建新会话

- Core: 新增 :new/:n 命令返回 new_session action
- Server: 处理 new_session action 创建新会话
- UI: useChat 添加 onSessionSwitch 回调
- Web/Desktop: ChatPage 和 App 实现会话切换逻辑

packages/core/src/system-commands/builtin/index.ts

@@ -4,12 +4,14 @@
 
 import type { SystemCommand } from '../types.js';
 import { clearCommand } from './clear.js';
+import { newCommand } from './new.js';
 
 /**
  * 所有内置系统命令
  */
 export const builtinSystemCommands: SystemCommand[] = [
   clearCommand,
+  newCommand,
 ];
 
-export { clearCommand };
+export { clearCommand, newCommand };

packages/core/src/system-commands/builtin/new.ts

@@ -0,0 +1,22 @@
+/**
+ * :new 系统命令
+ *
+ * 创建新会话并切换到新会话
+ */
+
+import type { SystemCommand } from '../types.js';
+
+export const newCommand: SystemCommand = {
+  name: 'new',
+  description: '创建新会话并切换',
+  aliases: ['n'],
+  execute: async (_context) => {
+    // 实际的创建操作由 Server 层处理
+    // 这里只返回操作指令
+    return {
+      success: true,
+      message: '正在创建新会话...',
+      action: { type: 'new_session' },
+    };
+  },
+};

packages/desktop/src/pages/Chat.tsx

@@ -16,6 +16,8 @@ import {
 interface ChatPageProps {
   sessionId: string;
   onSessionUpdated?: (sessionId: string, name: string) => void;
+  /** 切换会话回调（如 :new 命令创建新会话） */
+  onSessionSwitch?: (newSessionId: string) => void;
   // 工具栏按钮
   showFileBrowser?: boolean;
   onToggleFileBrowser?: () => void;
@@ -31,6 +33,7 @@ interface ChatPageProps {
 export function ChatPage({
   sessionId,
   onSessionUpdated,
+  onSessionSwitch,
   showFileBrowser,
   onToggleFileBrowser,
   onOpenConfig,
@@ -55,6 +58,7 @@ export function ChatPage({
       console.error('Chat error:', error);
     },
     onSessionUpdated,
+    onSessionSwitch,
     onConfigError: (error) => {
       toast.error(error.message, {
         duration: 10000,

packages/server/src/ws.ts

@@ -322,7 +322,19 @@ async function handleSystemCommand(sessionId: string, content: string): Promise<
         sessionManager.updateStatus(sessionId, 'idle');
         break;
       }
-      // 可以在这里添加其他操作类型的处理
+
+      case 'new_session': {
+        // 获取当前会话信息以复用配置
+        const currentSession = sessionManager.get(sessionId);
+        const workdir = currentSession?.workdir || process.cwd();
+
+        // 创建新会话
+        const newSession = await sessionManager.create({ workdir });
+
+        // 更新 action 中的 sessionId
+        result.action = { type: 'new_session', sessionId: newSession.id };
+        break;
+      }
     }
   }
 

packages/ui/src/hooks/useChat.ts

@@ -33,6 +33,8 @@ interface UseChatOptions {
   onSessionUpdated?: (sessionId: string, name: string) => void;
   /** 配置错误回调（如 API Key 未配置） */
   onConfigError?: (error: ConfigErrorPayload) => void;
+  /** 切换会话回调（如 :new 命令创建新会话） */
+  onSessionSwitch?: (newSessionId: string) => void;
 }
 
 interface ChatState {
@@ -52,7 +54,7 @@ interface ChatState {
   currentSubagent: SubagentState | null;
 }
 
-export function useChat({ sessionId, onError, onSessionNotFound, onSessionUpdated, onConfigError }: UseChatOptions) {
+export function useChat({ sessionId, onError, onSessionNotFound, onSessionUpdated, onConfigError, onSessionSwitch }: UseChatOptions) {
   const [state, setState] = useState<ChatState>({
     messages: [],
     isConnected: false,
@@ -77,10 +79,12 @@ export function useChat({ sessionId, onError, onSessionNotFound, onSessionUpdate
   const onSessionNotFoundRef = useRef(onSessionNotFound);
   const onSessionUpdatedRef = useRef(onSessionUpdated);
   const onConfigErrorRef = useRef(onConfigError);
+  const onSessionSwitchRef = useRef(onSessionSwitch);
   onErrorRef.current = onError;
   onSessionNotFoundRef.current = onSessionNotFound;
   onSessionUpdatedRef.current = onSessionUpdated;
   onConfigErrorRef.current = onConfigError;
+  onSessionSwitchRef.current = onSessionSwitch;
 
   // 加载历史消息
   const loadMessages = useCallback(async () => {
@@ -572,7 +576,7 @@ export function useChat({ sessionId, onError, onSessionNotFound, onSessionUpdate
               success: boolean;
               message?: string;
               error?: string;
-              action?: { type: string };
+              action?: { type: string; sessionId?: string };
             };
 
             // 处理清空消息操作
@@ -585,6 +589,11 @@ export function useChat({ sessionId, onError, onSessionNotFound, onSessionUpdate
               }));
             }
 
+            // 处理新建会话操作
+            if (payload.success && payload.action?.type === 'new_session' && payload.action.sessionId) {
+              onSessionSwitchRef.current?.(payload.action.sessionId);
+            }
+
             // 如果有错误，通过 onError 回调通知
             if (!payload.success && payload.error) {
               onErrorRef.current?.(new Error(payload.error));

packages/web/src/App.tsx

@@ -103,6 +103,11 @@ export function App() {
     setSessionTitleUpdate({ sessionId, name });
   }, []);
 
+  // 会话切换回调（:new 命令创建新会话后切换）
+  const handleSessionSwitch = useCallback((newSessionId: string) => {
+    setCurrentSessionId(newSessionId);
+  }, []);
+
   // 处理面板宽度调整
   const handleResize = useCallback((delta: number) => {
     setIdePanelWidth((prev) => {
@@ -159,6 +164,7 @@ export function App() {
                 sessionId={currentSessionId}
                 onSessionNotFound={handleSessionNotFound}
                 onSessionUpdated={handleSessionUpdated}
+                onSessionSwitch={handleSessionSwitch}
                 responsive
                 onOpenCommands={() => setShowCommands(true)}
                 onOpenMCP={() => setShowMCP(true)}

packages/web/src/pages/Chat.tsx

@@ -22,6 +22,8 @@ interface ChatPageProps {
   sessionId: string;
   onSessionNotFound?: () => void;
   onSessionUpdated?: (sessionId: string, name: string) => void;
+  /** 切换会话回调（如 :new 命令创建新会话） */
+  onSessionSwitch?: (newSessionId: string) => void;
   responsive?: boolean;
   // 工具栏按钮
   onOpenCommands?: () => void;
@@ -39,6 +41,7 @@ export function ChatPage({
   sessionId,
   onSessionNotFound,
   onSessionUpdated,
+  onSessionSwitch,
   responsive = false,
   onOpenCommands,
   onOpenMCP,
@@ -74,6 +77,7 @@ export function ChatPage({
     },
     onSessionNotFound,
     onSessionUpdated,
+    onSessionSwitch,
     onConfigError: (error) => {
       toast.error(error.message, {
         duration: 10000,